133 research outputs found
Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at root s=10.6 GeV
No full textNew measurements of D-s(+) and D-s(*+) meson production rates from B decays and from q(q) over bar continuum events near the Y(4S) resonance are presented. Using 20.8 fb(-1) of data on the Y(4S) resonance and 2.6 fb(-1) off-resonance, we find the inclusive branching fractions B(B-->Ds+X) = (10.93+/-0.19+/-0.58+/-2.73)% and B(B-->Ds*+X) = (7.9+/-0.8+/-0.7+/-2.0)%, where the first error is statistical, the second is systematic, and the third is due to the D-s(+)-->phipi(+) branching fraction uncertainty. The production cross sections sigma(e(+)e(-)-->Ds+X)xB(D-s(+)-->phipi(+)) = 7.55+/-0.20+/-0.34 pb and sigma(e(+)e(-)-->Ds*+/-X)xB(D-s(+)-->phipi(+)) = 5.8+/-0.7+/-0.5 pb are measured at center-of-mass energies about 40 MeV below the Y(4S) mass. The branching fractions SigmaB(B-->D-s((*)+)(D) over bar ((*))) = (5.07+/-0.14+/-0.30+/-1.27)% and SigmaB(B-->D-s(*+)(D) over bar ((*))) = (4.1+/-0.2+/-0.4+/-1.0)% are determined from the D-s((*)+) momentum spectra. The mass difference m(D-s(+)) -m(D+) = 98.4+/-0.1+/-0.3 MeV/c(2) is also measured
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Model independent measurement of S-wave K- pi+ systems using D+ ---> K pi pi decays from Fermilab E791
No full textA model-independent partial-wave analysis of the S-wave component of the K{pi} system from decays of D{sup +} mesons to the three-body K{sup -}{pi}{sup +}{pi}{sup +} final state is described. Data come from the Fermilab E791 experiment. Amplitude measurements are made independently for ranges of K{sup -}{pi}{sup +} invariant mass, and results are obtained below 825 MeV/c{sup 2}, where previous measurements exist only in two mass bins. This method of parametrizing a three-body decay amplitude represents a new approach to analyzing such decays. Though no model is required for the S-wave, a parametrization of the relatively well-known reference P- and D-waves, optimized to describe the data used, is required. The observed phase variation for the S-, P- and D-waves do not match existing measurements of I = 1/2 K{sup -} {pi}{sup +} scattering in the invariant mass range in which scattering is predominantly elastic. If the data are mostly I = 1/2, this observation indicates that the Watson theorem, which requires these phases to have the same dependence on invariant mass, does not apply to these decays. The production rate of K{sup -}{pi}{sup +} from these decays, if assumed to be predominantly I = 1/2, is also found to have a significant dependence on invariant mass in the region above 1.25 GeV/c{sup 2}. These measurements can provide a relatively model-free basis for future attempts to determine which strange scalar amplitudes contribute to the decays
Measurement of D+(s) and D*+(s) production in B meson decays and from continuum e+ e- annihilations at s**(1/2) = 10.6-GeV
No full textNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the Υ(4S) resonance are presented. Using 20.8 fb-1 of data on the Υ(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the Υ(4S) mass. The branching fractions ΣB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ΣB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured
The BaBar detector
No full textThis is the pre-print version of the Article. The official published version can be accessed from the link below. Copyright @ 2002 Elsevier.BABAR, the detector for the SLAC PEP-II asymmetric e+e− B Factory operating at the (4S) resonance, was designed to allow comprehensive studies of CP-violation in B-meson decays. Charged particle tracks are measured in a multi-layer silicon vertex tracker surrounded by a cylindrical wire drift chamber. Electromagnetic showers from electrons and photons are detected in an array of CsI crystals located just inside the solenoidal coil of a superconducting magnet. Muons and neutral hadrons are identified by arrays of resistive plate chambers inserted into gaps in the steel flux return of the magnet. Charged hadrons are identified by dE/dx measurements in the tracking detectors and in a ring-imaging Cherenkov detector surrounding the drift chamber. The trigger, data acquisition and data-monitoring systems , VME- and network-based, are controlled by custom-designed online software. Details of the layout and performance of the detector components and their associated electronics and software are presented.This work has been supported by the US Department of Energy and the National Science
Foundation, the Natural Sciences and Engineering Research Council (Canada), the Institute of High Energy Physics (P.R. China), le Commisariat a l’Energie Atomique and Institut National de Physique Nucl´eaire et de Physique des Particules (France), Bundesministerium fur Bildung und Forschung (Germany), Istituto Nazionale di Fisica Nucleare (Italy), the Research Council of
Norway, the Ministry of Science and Technology of the Russian Federation, and the Particle Physics and Astronomy Research Council (United Kingdom). In addition, individuals have received support from the Swiss National Foundation, the A.P. Sloan Foundation, the Research Corporation, and the Alexander von Humboldt Foundation
Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at √s=10.6 GeV
No full textThis is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the Υ(4S) resonance are presented. Using 20.8 fb-1 of data on the Υ(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the Υ(4S) mass. The branching fractions ΣB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ΣB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
A measurement of the charged and neutral B meson lifetimes using fully reconstructed decays
No full textThe author first notes that Google, the trade mark, the project, the utilization - the "googling"- are social facts proven by the numbers – number of net surfers, of requests, of uses- and by the signs of adhesion - linguistics, economic, social. A socio linguistic analysis of the speeches of the persons in charge of Google and of users indicate that the social fact "googling" results in the emergence of a culture and a world community which shares it. They are supported by the language and also by the myths that were created and largely maintained by the owners the mark "Google Inc". The conclusion is that the current organization of the market of services on the Internet makes that Google Inc. is almost the only institution to know the population of the googlers. In order not to be subjected to this monopoly, however comfortable it is, the author proposes to develop a research program on the uses and users of Google
A measurement of the charged and neutral B meson lifetimes using fully reconstructed decays
No full textThe author first notes that Google, the trade mark, the project, the utilization - the "googling"- are social facts proven by the numbers – number of net surfers, of requests, of uses- and by the signs of adhesion - linguistics, economic, social. A socio linguistic analysis of the speeches of the persons in charge of Google and of users indicate that the social fact "googling" results in the emergence of a culture and a world community which shares it. They are supported by the language and also by the myths that were created and largely maintained by the owners the mark "Google Inc". The conclusion is that the current organization of the market of services on the Internet makes that Google Inc. is almost the only institution to know the population of the googlers. In order not to be subjected to this monopoly, however comfortable it is, the author proposes to develop a research program on the uses and users of Google
The BaBar detector: Upgrades, operation and performance
No full textContains fulltext :
121729.pdf (Author’s version preprint ) (Open Access
A Study of time dependent CP violating asymmetries in B0 ---> J / psi K0(s) and B0 ---> psi(2S) K0(s) decays
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